GregP
Major
Mass only cancels out if the masses of two different aircraft are nearly equal. If they are substantially different, then the masses make a big difference.
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Mass only cancels out if the masses of two different aircraft are nearly equal. If they are substantially different, then the masses make a big difference.Hello GregP,
Of all the people in this discussion, you and Shortround6 are the two that I would have expected the least argument for this line of thought.
The point I keep trying to make is that Mass is in both the PE and KE equations and therefore cancel each other out.
A WW2 aircraft flying to a hammerhead stall isn't behaving a whole lot different than the Streak Eagle.
Let's consider THIS situation:
We have two identical P-47 Thunderbolts.
One has a full load of fuel and ammunition. The other has no ammunition and much less fuel.
Figure one is 1500 pounds heavier than the other.
Both pull into a zoom climb at same angle and from the same initial level speed.
Which one will go higher?
Why?
Yes, one will have a bit more induced drag, but..... The additional weight should give it an advantage.
What do you really think?
You are still not understanding. We are not talking about TWO different aircraft.Mass only cancels out if the masses of two different aircraft are nearly equal. If they are substantially different, then the masses make a big difference.
You can put as much weight as you like into Fokker Tri plane and it doesnt affect the maximum speed in a dive because the wings come off. The Hurricane with fabric and dope wings was heavier than one with metal wings but the maximum dive speed was lower, because the fabric started to balloon and tear.You CAN quote the laws of physics pretty much until you get close to relativistic speeds and we are certainly not there in regards to any know aircraft or even spacecraft. They don't really chance much as we might want them to sometimes.
Everything else affecting a zoom climb is "part of the discussion". I was pointing out that weight canceled itself out as far as KE to PE conversion. The difference had to be aerodynamic effects such as streamlining and the relative effects of air on the vehicle, thus the mention of Reynolds number as a possible factor in the calculation.
Sounds like you need more buzz practice!
You CAN quote the laws of physics pretty much until you get close to relativistic speeds and we are certainly not there in regards to any know aircraft or even spacecraft. They don't really chance much as we might want them to sometimes.
Everything else affecting a zoom climb is "part of the discussion". I was pointing out that weight canceled itself out as far as KE to PE conversion. The difference had to be aerodynamic effects such as streamlining and the relative effects of air on the vehicle, thus the mention of Reynolds number as a possible factor in the calculation.
How can it be the SAME aircraft? We've been talking about zoom climb comparisons. If you only have one airplane, then it can't zoom climb better or worse than itself. It can only climb better or worse versus some other airplane that almost certainly doesn't mass the same.You are still not understanding. We are not talking about TWO different aircraft.
We are talking about ONE aircraft with a lot of KE in level flight and converting that KE into PE for altitude.
It is the SAME aircraft, so mass doesn't change except for a small amount of fuel burned during the zoom.
You can put as much weight as you like into Fokker Tri plane and it doesnt affect the maximum speed in a dive because the wings come off. The Hurricane with fabric and dope wings was heavier than one with metal wings but the maximum dive speed was lower, because the fabric started to balloon and tear.
Doesn't mass retain inertia better?
How can it be the SAME aircraft? We've been talking about zoom climb comparisons. If you only have one airplane, then it can't zoom climb better or worse than itself. It can only climb better or worse versus some other airplane that almost certainly doesn't mass the same.
If you compare, for instance, a P-40N versus a Spitfire V, then the P-40N will be about 8,500 pounds and the Spitfire V will be about 6,300 pounds. The P-40 is about 35% heavier and thus, at the same altitude and speed, has about 35% more PE and about 35% more KE since ET = mgh + 1/2 m V^2; and g, h, and V are the same, leaving only mass as the difference. One airplane has only itself to compare with. It doesn't make sense to be talking about only one airplane and put the word "comparison" in the sentence. Compare implies more than one choice.
If you have a P-36 and P-40 loaded to the same weight, at the same height and velocity, producing the same power, then you can compare them. They will NOT zoom-climb the same.
You cannot have the same aerodynamics, whatever weight you have needs to be lifted, that lift is provided by the wings, to change from level flight you need to increase the AoA to provide that lift and climb, to climb with more weight needs more lift. I associate zoom climb to be a climb rate from a speed not attainable in level flight as in "boom and zoom" tactics, obviously you dont, could you please clarify the difference between "zoom climb" and "maximum climb rate" in your thinking.Hello PBehn,
We are discussing Zoom Climbs, not Terminal Velocity Dives.
We are starting off in Level Flight at some speed and trade off that speed for altitude which means we end up going only slower.
The question I was asking GregP was whether he thought an aircraft would zoom higher or faster if it had the SAME aerodynamics but just additional weight.
When we start talking about structural limitations of various airframes and when they fall apart in a dive, it becomes a whole different subject.
Are you discussing it being easier to climb with more weight?Hello GregP,
Of all the people in this discussion, you and Shortround6 are the two that I would have expected the least argument for this line of thought.
The point I keep trying to make is that Mass is in both the PE and KE equations and therefore cancel each other out.
A WW2 aircraft flying to a hammerhead stall isn't behaving a whole lot different than the Streak Eagle.
Let's consider THIS situation:
We have two identical P-47 Thunderbolts.
One has a full load of fuel and ammunition. The other has no ammunition and much less fuel.
Figure one is 1500 pounds heavier than the other.
Both pull into a zoom climb at same angle and from the same initial level speed.
Which one will go higher?
Why?
Yes, one will have a bit more induced drag, but..... The additional weight should give it an advantage.
What do you really think?
Absolutely!
Increased Mass retains Inertia better but it also gets pulled down harder by Gravity.
Funny thing is that the two balance out EXACTLY which is what a fellow named Galileo is supposed to have proved at the Tower of Pisa. That is why all objects fall at the same speed and acceleration with differences being the result of the relative effects of air resistance.
If all objects fall at the same speed (per Galileo), but more mass retains more inertia (per Newton), wouldn't that leave a heavier aircraft with more inertia as it begins its climb out of a dive?
I'm not studied in physics and am not equipped to argue that, but it seems odd to me that if gravity works the same no matter the mass, but inertia is tied to mass, why mass wouldn't have an impact on a zoom climb. Per 2LOT that energy has to go somewhere. Might you explain further?
You are correct. An aircraft with twice as much mass (weighing twice as much) would have twice as much inertia resisting change in velocity.
Note that for all practical purposes Weight is proportional to Mass, so the aircraft with twice the mass and twice the inertia also has twice the Gravitational attraction (gravitation acceleration) slowing it down as it climbs or speeding it up as it dives.
Per Newton, we have F = M * A
but F == M * G(The Gravitational Constant) so A is the same.
The Kinetic Energy DOES go somewhere. It gets transformed into the Potential Energy of the Mass of the Aircraft at a greater height.
You cannot have the same aerodynamics, whatever weight you have needs to be lifted, that lift is provided by the wings, to change from level flight you need to increase the AoA to provide that lift and climb, to climb with more weight needs more lift. I associate zoom climb to be a climb rate from a speed not attainable in level flight as in "boom and zoom" tactics, obviously you dont, could you please clarify the difference between "zoom climb" and "maximum climb rate" in your thinking.
Sorry Ivan, I was addressing the OP's first post, not post # 20.Hello GregP,
Of all the people in this discussion, you and Shortround6 are the two that I would have expected the least argument for this line of thought.
The point I keep trying to make is that Mass is in both the PE and KE equations and therefore cancel each other out.
A WW2 aircraft flying to a hammerhead stall isn't behaving a whole lot different than the Streak Eagle.
Let's consider THIS situation:
We have two identical P-47 Thunderbolts.
One has a full load of fuel and ammunition. The other has no ammunition and much less fuel.
Figure one is 1500 pounds heavier than the other.
Both pull into a zoom climb at same angle and from the same initial level speed.
Which one will go higher?
Why?
Yes, one will have a bit more induced drag, but..... The additional weight should give it an advantage.
What do you really think?
So mass does indeed have an impact on zoom?
Here is a silly question for you:In a vacuum, there will be no lift, so there will be no climb, zoom or otherwise. Therefore mass DOES have an impact on zoom climb since there must be air and air resistance in order to produce lift ... unless this is pointless question to harass people who have enough interest to spend time thinking about it ...
Are you laughing, Ivan1GFP? If it ain't fun, what's the point?
Maybe our reach exceeds our grasp.